> This is frankly total BS
> and implies a profound ignorance of the whole subject of intelligence.
Really!?! In my freely admitted "ignorance" of the subject, I would argue that there is a profound possibility of variance in human intelligence based on such things as variabilities in neurotransmitter release and uptake by receptors -- for which there are known to be genetic "variants". These variants would be diminished or eliminated in twins, and so one would expect there to be a correlation in the intelligence of such individuals. Are you attacking a specific set of twin studies or the entire concept that intelligence can have a basis in molecular biology and genetics?
> In fact, this is part and parcel of the whole Mensa nonsense propagated by
> Mensa founder Cyril Burt in his massively fraudulent Twin Study, very likely
> the most costly scientific fraud in all history.
Fraud or not fraud, you be the judge. Do you have an explanation or argument that variations in genetic traits that effect brain development such as (#'s of neurons, rate of neuronal death, reinforcement of synaptic strength/weightings, neurotransmitter release & uptake rates, propagation rates of neuronal impulses) are *totally* negated by environmental effects?
> stack of documentation from U of Chicago that resulted in Head Start.
> Or the nearly century-long record of Montessori education.
Do you have *specific* references here?
I would argue that if either Head Start or Montessori educations had made a demonstrable difference in the intelligence of children that you would see parents flocking to these approaches. If they only have marginal effects within a range of intelligences dictated primarily by genetic factors, then I would argue that you would have what you see today -- that people adhere to these approaches to the degree that they have been convinced that they have some benefit. Such benefit is "marginal" and that is why the subscription base is marginal as well.